Any contractor can do this job.... and you don have to do it.. the job is not hard but difficult in the sense that labour demanding that you need to climb, sustain ray from burning sun etc.

what roof are you using? concrete? metaldec?

a typical sandwich system is more than sufficient for insulation...

top layer- roof
2nd layer polywool fibreglass density=24kg/m^3
3rd layer- aluminium foil, reflectivity >95%
4th layer- S/S mesh to withheld the above(aluminium foil & fibre wool)

another factor also factor in.. air ventilation

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Added on April 27, 2011, 10:30 am
heat enters house via roof with significantly >50%

wall another 30-40%

so, material selection is very important

was quoted Radenshield Woven AL $400 , 1.25 X 48m per roll.

radent shield by Monier... can get from any hardware shop selling monier tiles...
http://www.monier.com.my/products-services...nt-barrier.html

DuoFoil by HongLeong Industry. Also by any hardware shop
http://www.hlm.com.my/Duofoil.html

N.B dont even call the number on the web to buy.. unless you are goin to buy >100 roll from them.....

p/s insulation roof come in a system... not a single product.... so, you can use a super duper radient barrier but not efficient system/installation wont show how effective the super duper product is...

it is like attach a F1 tyre onto a kancil...